Apparatus for enhancing electrolyte wetting in rechargeable battery and electrolyte wetting enhancing method using the same

ABSTRACT

An apparatus for enhancing electrolyte wetting in a rechargeable battery, which can improve an electrolyte wetting dispersion and enhancing electrolyte wetting in the rechargeable battery by vacuating gases trapped in an electrode assembly by injecting an electrolyte into the electrode assembly and pushing the rechargeable battery, and an electrolyte wetting enhancing method utilizing the same. The electrolyte wetting enhancing apparatus includes a chamber having an internal space; a battery fixing unit fixed in the internal space of the chamber and including a plurality of rechargeable batteries mounted therein; and a pushing member pushing opposite side surfaces of the plurality of rechargeable batteries. The pushing member pushes the plurality of rechargeable batteries to enhance electrolyte wetting into an electrode assembly including the plurality of rechargeable batteries into which the electrolyte is injected.

CROSS-REFERENCE TO RELATED APPLICATION

This application claims priority to and the benefit of Korean PatentApplication No. 10-2015-0152224, filed on Oct. 30, 2015, in the KoreanIntellectual Property Office, the disclosure of which is incorporatedherein by reference in its entirety.

BACKGROUND

1. Field

The following description relates to an apparatus for enhancingelectrolyte wetting in a rechargeable battery and an electrolyte wettingenhancing method utilizing the same.

2. Description of the Related Art

Recently, with the increasing demand for portable electronic devices,demand for rechargeable batteries as energy sources is rapidlyincreasing. In particular, lithium rechargeable batteries are receivinglots of (e.g., the highest) attention due to their high capacity.

Along with the high capacity of rechargeable batteries, since an activematerial composite density may increase, electrolyte wetting of anelectrode is becoming more and more important. If electrolyte wettingcapability is poor in manufacturing a rechargeable battery, the capacityof the rechargeable battery may be lowered and the electrode reactionsmay concentrate on local regions, resulting in the local precipitationof lithium metal, thereby lowering the stability of the rechargeablebattery.

In addition, as the size of an electrode plate is increased, a timerequired for electrolyte wetting may also be increased, thereby loweringthe manufacturability (e.g., productivity) of rechargeable batteries.Further, non-uniform electrolyte wetting may deteriorate electrodecharacteristics, thereby shortening a cycle life of the battery.

SUMMARY

Aspects according to one or more embodiments of the present inventionare directed toward an apparatus for enhancing electrolyte wetting in arechargeable battery, which can improve an electrolyte wettingdispersion and enhancing electrolyte wetting in the rechargeable batteryby vacuating gases trapped in an electrode assembly by injecting anelectrolyte into the electrode assembly and pushing the rechargeablebattery; and an electrolyte wetting enhancing method utilizing theelectrolyte wetting enhancing apparatus.

Aspects according to one or more embodiments of the present inventionare also directed toward an apparatus for enhancing electrolyte wettingin a rechargeable battery, which can improve an electrolyte wettingdispersion and enhancing electrolyte wetting in the rechargeable batteryby adopting a pressure difference between the inside and the outside ofa pouch; and an electrolyte wetting enhancing method utilizing theelectrolyte wetting enhancing apparatus.

The above and other aspects of the present invention will be describedin the following description of exemplary embodiments, or will beapparent from the following description of exemplary embodiments.

According to an embodiment of the present invention, an apparatus forenhancing electrolyte wetting in a rechargeable battery includes achamber having an internal space; a battery fixing unit in the internalspace of the chamber and configured to have a plurality of rechargeablebatteries mounted therein; and a pushing member configured to pushopposite side surfaces of the plurality of rechargeable batteries. Thepushing member is configured to push the plurality of rechargeablebatteries to enhance electrolyte wetting into an electrode assembly ofeach of the plurality of rechargeable batteries into which theelectrolyte is injected.

The electrolyte wetting enhancing may further include a pressure pumpconnected to the chamber and configured to pressurize the chamber tomaintain the internal space of the chamber in a pressurized state.

The electrolyte wetting enhancing apparatus may further include a vacuumpump connected to the chamber and configured to vacuate the chamber tocreate a vacuum state.

According to another embodiment of the present invention, a method forenhancing electrolyte wetting in a rechargeable battery includesinjecting an electrolyte into a plurality of rechargeable batteriesmounted in a battery fixing unit provided in an internal space of achamber; and pushing opposite side surfaces of the plurality ofrechargeable batteries into which the electrolyte is injected utilizinga pushing member at a constant time interval.

After the injecting of the electrolyte, the electrolyte wettingenhancing method may further include sealing the plurality ofrechargeable batteries.

The pushing member may push the plurality of rechargeable batteries atthe constant time interval of 20 to 30 times per minute for 3 to 8minutes.

After the injecting of the electrolyte, the electrolyte wettingenhancing method may further include pressurizing the chamber by drivinga pressure pump to maintain the internal space of the chamber in apressurized state.

The plurality of rechargeable batteries may be pushed in a state inwhich the internal space of the chamber is maintained in a vacuum stateby vacuating the chamber by driving the pressure pump.

In the pressurizing of the chamber, the chamber is pressurized tomaintain the internal space of the chamber in the pressurized state of 4to 8 bar, and in the pushing of the opposite side surfaces, thepressurized state of the internal space of the chamber is decompressedto −40 to −80 kPa.

After the pushing of the opposite side surfaces, the electrolyte wettingenhancing method may further include sealing the plurality ofrechargeable batteries in a vacuum state.

As described above, in the electrolyte wetting enhancing apparatus in arechargeable battery according to an embodiment of the present inventionand in the electrolyte wetting enhancing method utilizing theelectrolyte wetting enhancing apparatus, an electrolyte wettingdispersion can be improved and electrolyte wetting in the rechargeablebattery can be enhanced by vacuating gases trapped in an electrodeassembly by injecting an electrolyte into the electrode assembly andpushing the rechargeable battery.

Also, in the electrolyte wetting enhancing apparatus in a rechargeablebattery according to an embodiment of the present invention and in theelectrolyte wetting enhancing method utilizing the electrolyte wettingenhancing apparatus, an electrolyte wetting dispersion can be improvedand electrolyte wetting in the rechargeable battery can be enhanced byadopting a pressure difference between the inside and the outside of apouch.

BRIEF DESCRIPTION OF THE DRAWINGS

The above and other features of the present invention will become moreapparent by describing in more detail exemplary embodiments thereof withreference to the attached drawings in which:

FIG. 1 is a schematic view illustrating a structure of an electrolytewetting enhancing apparatus in a rechargeable battery according to anembodiment of the present invention;

FIG. 2 is a side view illustrating an internal structure of a chamber inthe electrolyte wetting enhancing apparatus shown in FIG. 1;

FIG. 3 is a cross-sectional view illustrating a rechargeable batterymounted in a battery fixing unit of the electrolyte wetting enhancingapparatus shown in FIG. 1;

FIG. 4 is a flowchart illustrating an exemplary electrolyte wettingenhancing method of the electrolyte wetting enhancing apparatus shown inFIG. 1; and

FIG. 5 is a flowchart illustrating another exemplary electrolyte wettingenhancing method of the electrolyte wetting enhancing apparatus shown inFIG. 1.

DETAILED DESCRIPTION

Hereinafter, examples of embodiments of the invention will be describedin more detail with reference to the accompanying drawings such thatthey can easily be made and used by those skilled in the art. Thepresent invention may, however, be embodied in many different forms andshould not be construed as being limited to the embodiments set forthherein. Rather, these embodiments are provided so that this disclosurewill be thorough and complete and will fully convey the concept of theinvention to those skilled in the art.

In the drawings, the thickness of layers and regions are exaggerated forclarity. Like numbers refer to like elements throughout. As used herein,the term “and/or” includes any and all combinations of one or more ofthe associated listed items. Also, the term “exemplary” is intended torefer to an example or illustration. As used herein, the terms“substantially,” “about,” and similar terms are used as terms ofapproximation and not as terms of degree, and are intended to accountfor the inherent deviations in measured or calculated values that wouldbe recognized by those of ordinary skill in the art. Also, any numericalrange recited herein is intended to include all sub-ranges of the samenumerical precision subsumed within the recited range. For example, arange of “1.0 to 10.0” is intended to include all subranges between (andincluding) the recited minimum value of 1.0 and the recited maximumvalue of 10.0, that is, having a minimum value equal to or greater than1.0 and a maximum value equal to or less than 10.0, such as, forexample, 2.4 to 7.6. Any maximum numerical limitation recited herein isintended to include all lower numerical limitations subsumed therein andany minimum numerical limitation recited in this specification isintended to include all higher numerical limitations subsumed therein.Accordingly, Applicant reserves the right to amend this specification,including the claims, to expressly recite any sub-range subsumed withinthe ranges expressly recited herein.

In addition, the terminology used herein is for the purpose ofdescribing particular embodiments only and is not intended to belimiting thereof. As used herein, the singular forms are intended toinclude the plural forms as well, unless the context clearly indicatesotherwise. It will be further understood that the terms “comprise”and/or “comprising,” when used in this specification, specify thepresence of stated features, integers, steps, operations, elements,and/or components, but do not preclude the presence or addition of oneor more other features, integers, steps, operations, elements,components, and/or groups thereof.

It will be understood that, although the terms first, second, etc. maybe used herein to describe various members, elements, regions, layersand/or sections, these members, elements, regions, layers and/orsections should not be limited by these terms. These terms are only usedto distinguish one member, element, region, layer, and/or section fromanother. Thus, for example, a first member, a first element, a firstregion, a first layer and/or a first section discussed below could betermed a second member, a second element, a second region, a secondlayer and/or a second section without departing from the teachings.

Referring to FIG. 1, a schematic view illustrating a structure of anelectrolyte wetting enhancing apparatus in a rechargeable batteryaccording to an embodiment of the present invention is illustrated.Referring to FIG. 2, a side view illustrating an internal structure of achamber in the electrolyte wetting enhancing apparatus shown in FIG. 1is illustrated. Referring to FIG. 3, a cross-sectional view illustratinga rechargeable battery mounted in a battery fixing unit of theelectrolyte wetting enhancing apparatus shown in FIG. 1 is illustrated.Hereinafter, a structure of an electrolyte wetting enhancing apparatus100 in a rechargeable battery according to an embodiment of the presentinvention will be described with reference to FIGS. 1 to 3.

As illustrated in FIG. 1, the electrolyte wetting enhancing apparatus100 in a rechargeable battery includes a chamber 110, a battery fixingunit 120 accommodated in the chamber 110 and having a plurality ofrechargeable batteries 10 fixed thereto, and a pushing member 130applying a pressure to a plurality of rechargeable batteries 10 bypushing the plurality of rechargeable batteries 10 (e.g., by pushing twoopposite side surfaces of each of the plurality of rechargeablebatteries to move towards each other) at a constant time interval. Inaddition, the electrolyte wetting enhancing apparatus 100 may furtherinclude a vacuum pump 140 vacuating the chamber 110 to create a vacuumstate in the chamber 110, and a pressure pump 150 for increasing aninternal pressure of the chamber 110.

Each of the plurality of rechargeable batteries 10 may include anelectrode assembly 1 (formed by interposing a separator as an insulatorbetween a positive electrode plate and a negative electrode plate) and athin flexible pouch incorporating the electrode assembly 1. That is, theplurality of rechargeable batteries 10 may be pouch type batteries eachhaving the electrode assembly 1 accommodated in an internal spaceprovided by welding edges of the thin flexible pouch. The electrodeassembly 1 may be formed by stacking the positive electrode plate, theseparator and the negative electrode plate and winding the stackedstructure into a jelly-roll shape.

In each of the plurality of rechargeable batteries 10, the positiveelectrode plate and the negative electrode plate are electricallyconnected to a positive electrode tab 11 and a negative electrode tab12, respectively, which are exposed to the outside through weldedportions of one side of the pouch. The plurality of rechargeablebatteries 10 may have planar long side surfaces 10 a facing each other.For example, the pouch of each of the plurality of rechargeablebatteries 10 may have a planar top side surface and a planar bottom sidesurface facing the planar top side surface, and four side surfacesconnecting the top side surface and the bottom side surface. The fourside surfaces may each include a welded portion, and may be configuredsuch that the welded portion of one of the side surfaces (excluding theside surface of the pouch having the welded portions through which thepositive electrode tab 11 and the negative electrode tab 12 are exposedto the outside), among the four sides of each of the long side surfaces10 a, may not be welded prior to the injection of the electrolyte. Thatis, the welded portions of one side of each of the plurality ofrechargeable batteries 10 may be opened. A rounded side surface (amongthe four side surfaces connecting a top side surface and a bottom sidesurface) of the electrode assembly 1 may be exposed to the outsidethrough one open side 10 b of each of the plurality of rechargeablebatteries 10.

The chamber 110 has an internal space. The chamber 110 may include alower case and an upper cover, which are engaged with each other afterthe plurality of rechargeable batteries 10 are mounted in the chamber110, thereby hermetically closing the internal space.

The battery fixing unit 120 may be mounted and fixed in the internalspace of the chamber 110. The battery fixing unit 120 may be in theshaped of a frame. The plurality of rechargeable batteries 10 may bedetachably mounted in an internal space of the frame of the batteryfixing unit 120. The plurality of rechargeable batteries 10 may bealigned in the battery fixing unit 120 such that the two long sidesurfaces (e.g., the top and bottom side surfaces) are exposed to theoutside (e.g., not covered by the frame of the battery fixing unit 120)and the opened welded portions face upward. In addition, the long sidesurfaces of the plurality of rechargeable batteries 10 may be coplanarlypositioned. The plurality of rechargeable batteries 10 may be mounted inthe battery fixing unit 120 to be spaced apart from each other, butaspects of the present invention are not limited thereto.

The pushing member 130 may include (e.g., consist of) two flat panels131 facing each other, and may be mounted within the chamber 110.

The pushing member 130 may be mounted in the chamber 110 to face the twolong side surfaces (e.g., the top and bottom side surfaces) of theplurality of rechargeable batteries 10. The pushing member 130 mayinclude (e.g., consist of) a set (e.g., a set of panels) having twoplanar panels facing each other. The pushing member 130 may include(e.g., consist of) a plurality of sets, that is, as many sets as theplurality of rechargeable batteries 10, so as to individually push(e.g., apply pressure to) the plurality of rechargeable batteries 10.However, the pushing member 130 may include (e.g., consist of) a singleset to push the plurality of rechargeable batteries 10 at a time (e.g.,at the same time). However, the present invention does not limit thenumber of sets of the pushing member 130. The pushing member 130 may beelectrically connected to a driver and may be driven by controlling thedriver. The pushing member 130 may push opposite long side surfaces ofeach of the rechargeable batteries 10 at the same time interval or at aconstant time interval.

The vacuum pump 140 may be a pump vacuating the chamber 110 to create avacuum state of a set or predetermined pressure. The vacuum pump 140 maybe mounted outside the chamber 110 and may exhaust the internal air ofthe chamber 110, thereby maintaining the internal space of the chamber110 in the vacuum state.

The pressure pump 150 may be a pump pressurizing the chamber 110 tomaintain the internal space of the chamber 110 in a pressurized state ofa set or predetermined pressure. The pressure pump 150 may be mountedoutside the chamber 110 and may maintain the internal space of thechamber 110 in the pressurized state of a set or predetermined pressureby supplying gas (e.g., gases) to the internal space of the chamber 110.

Hereinafter, an electrolyte wetting enhancing method utilizing theelectrolyte wetting enhancing apparatus 100 in a rechargeable batterywill be described with reference to FIG. 4. As illustrated in FIG. 4,the electrolyte wetting enhancing method utilizing the electrolytewetting enhancing apparatus 100 may include acts (e.g., steps) ofinjecting an electrolyte and then pushing.

First, the plurality of rechargeable batteries 10 are mounted in thebattery fixing unit 120 provided within the chamber 110. Thereafter, theelectrolyte is injected into a pouch through the open side 10 b of eachof the plurality of rechargeable batteries 10 mounted in the chamber 110(S1).

After the injecting of the electrolyte (S1), in the pushing (S2), theplurality of rechargeable batteries 10 are pushed (e.g., pressed) by thepushing member 130 at a constant time interval. That is, the pushingmember 130 may push opposite long side surfaces of each of therechargeable batteries 10 at the same time interval or at a constanttime interval. In one embodiment, the pushing member 130 may repeat theprocess of contacting the opposite side surfaces of each of therechargeable batteries 10 to apply a set or predetermined force orpressure, and withdrawing to disengage from the opposite side surfacesof each of the rechargeable batteries 10 at a constant time interval.

The gas (e.g., gases) trapped in the electrode assembly 1 of each of therechargeable batteries 10 may be exhausted (e.g., discharged) to theoutside (of the rechargeable battery) by the pushing member 130. Forexample, the pushing member 130 may push the plurality of rechargeablebatteries 10 (e.g., apply pressure to the top and bottom side surfaces)at the constant time interval of 20 to 30 times per minute (e.g., theprocess of contacting the opposite side surfaces of each of therechargeable batteries 10 to apply a set or predetermined force orpressure, and withdrawing to disengage from the opposite side surfacesof each of the rechargeable batteries 10 is repeated 20 to 30 times perminute). In addition, in order to enhance electrolyte wetting into theelectrode assembly 1, the pushing member 130 may push the plurality ofrechargeable batteries 10 for at least 3 minutes (e.g., the process ofcontacting the opposite side surfaces of each of the rechargeablebatteries 10 to apply a set or predetermined force or pressure, andwithdrawing to disengage from the opposite side surfaces of each of therechargeable batteries 10 is repeated at a set or predetermined timeinterval of 20 to 30 times per minute for 3 to 8 minutes). In thepushing (S1), the gas (e.g., gases) trapped in the electrode assembly 1may be removed by pushing the plurality of rechargeable batteries 10. Inaddition, as described above, in the plurality of rechargeable batteries10, an electrolyte wetting dispersion can be improved by exhausting thegases trapped in the electrode assembly 1. Further, a time required forapparent electrolyte wetting to reach 100% may be shortened byexhausting the internal gases trapped in the electrode assembly 1 in thepushing (i.e., the act of pushing) (S2).

After the pushing (S2), the open side 10 b of each of the plurality ofrechargeable batteries 10 may be sealed (S3). However, the sealing (S3)may be performed between the injecting of the electrolyte (S1) and thepushing (S2). That is, in a case where electrolyte wetting of theplurality of rechargeable batteries 10 is enhanced just by the pushingmember 130, the sealing (S3) of the open side 10 b of the rechargeablebattery 10 may be performed before or after the pushing (S2).

In order to further enhance electrolyte wetting more than in theelectrolyte wetting enhancing method shown in FIG. 4, pressurizing (S2A)and pushing in a vacuum state (S2B) may be performed instead of thepushing (S2), as illustrated in FIG. 5. In addition, after the pushingin the vacuum state (S2B), sealing in a vacuum state (S3A) may beperformed.

In the pressurizing (S2A), the chamber 110 is pressurized to maintainthe internal space of the chamber 110 in a pressurized state. That is,in the pressurizing (S2A), the pressure pump 150 is driven to make theinternal space of the chamber 110 in the pressurized state, creating apressure difference between the inside and the outside of the pouch ofeach of the plurality of rechargeable batteries 10 into which theelectrolyte is injected. The pressure pump 150 pressurizes the chamber110 to maintain the internal space of the chamber 110 in the pressurizedstate of 4 to 8 bar. Here, the pressurized state is, for example,maintained for more than 3 minutes. If the internal space of the chamber110 is maintained in the pressurized state, the pouch of each of theplurality of rechargeable batteries 10 may be compressed due to thepressure difference between the inside and the outside of the pouch,thereby further enhancing the electrolyte wetting into the electrodeassembly 1.

In the pushing in a vacuum state (S2B), the internal space of thechamber 110 is decompressed to the vacuum state when the plurality ofrechargeable batteries 10 are pushed by the pushing member 130. That is,in the vacuum state, the plurality of rechargeable batteries 10 may beperiodically pushed by the pushing member 130. In this case, since apressure of the outside of the pouch is lower than that of the inside ofthe pouch (that is, the ourside of the pouch is in a vacuum), the gas(e.g., gases) trapped in the electrode assembly 1 of each of theplurality of rechargeable batteries 10 can be more efficientlyexhausted. As described above, the plurality of rechargeable batteries10 may have an improved electrolyte wetting dispersion by exhausting thegases trapped in the electrode assembly 1. The vacuum state of thechamber 110 may be created by driving the vacuum pump 140 to reach −40to −80 kPa (e.g., 40 to 80 kPa below atmosphere pressure). As describedabove, after the pressurizing (S2A) and the pushing in a vacuum state(S2B), a time required for apparent wetting to reach 100% may beshortened.

In addition, after the pushing in a vacuum state (S2B), the open side ofthe rechargeable battery 10 may be sealed in the vacuum state (S3A).That is, in order to enhance electrolyte wetting, the pressuredifference is created between the inside and the outside of the pouch ofthe rechargeable battery 10 in the pressurizing (S2A) and the pushing ina vacuum state (S2B). In addition, in order to improve an electrolytewetting dispersion, after the pressurizing (S2A) and the pushing in avacuum state (S2B), the sealing in a vacuum state (S3A) is performed.Here, the open side of the rechargeable battery 10 may be sealed in ahigh vacuum state of −90 kPa.

While the apparatus for enhancing electrolyte wetting in a rechargeablebattery and the enhancing method utilizing the same of the presentinvention have been particularly shown and described with reference toexemplary embodiments thereof, it will be understood by those ofordinary skill in the art that various changes in form and details maybe made therein without departing from the spirit and scope of thepresent invention as defined by the following claims and equivalentsthereof.

What is claimed is:
 1. An apparatus for enhancing electrolyte wetting ina rechargeable battery, the electrolyte wetting enhancing apparatuscomprising: a chamber having an internal space; a battery fixing unit inthe internal space of the chamber and configured to have a plurality ofrechargeable batteries mounted therein; and a pushing member configuredto push opposite side surfaces of the plurality of rechargeablebatteries, wherein the pushing member is configured to push theplurality of rechargeable batteries to enhance electrolyte wetting intoan electrode assembly of each of the plurality of rechargeable batteriesinto which the electrolyte is injected, wherein each of the plurality ofrechargeable batteries has a first side surface and a second sidesurface facing oppositely away from the first side surface, and a thirdside surface crossing the first and second side surfaces, wherein thethird side surface has an opening configured to receive the electrolyte,and the pushing member is configured to push the first side surface andsecond side surface toward each other.
 2. The electrolyte wettingenhancing apparatus of claim 1, further comprising a pressure pumpconnected to the chamber and configured to pressurize the chamber tomaintain the internal space of the chamber in a pressurized state. 3.The electrolyte wetting enhancing apparatus of claim 1, furthercomprising a vacuum pump connected to the chamber and configured tovacuate the chamber to create a vacuum state.
 4. The electrolyte wettingenhancing apparatus of claim 1, wherein the pushing member is configuredto repeat a process of contacting the first and second side surfaces ofeach of the plurality of rechargeable batteries to apply a set force orpressure, and withdrawing to disengage from the first and second sidesurfaces of each of the plurality of rechargeable batteries at asubstantially constant time interval.
 5. The electrolyte wettingenhancing apparatus of claim 1, wherein the battery fixing unit isconfigured to expose the first side surface, the second side surface,and the third side surface.